Electrical connector and method of making same.



No. 650,86I.

, Patentedlune 5, |900. T. J. MGTIGHE.

ELECTRICAL CONNECTOR AND METHOD 0F MAKING-SAIE.

(Appumion med mar. ao, 1900.)

(lo Modal.)

MM, W /w m m .w Md Mw UNITED. STATES PATENT OFFICE- THOMAS J. Marlena,or NEW YORK, N. Y.

ELECTRICAL coNNec-ron AND METHOD oF'MAK'mc SAME.

SPECIFICATION formingV part of Letters Patent No. 650,861, dated J une5, 1900'. Application filed Harel: 30, 1900. Serial No. 10,838. (Nomodcl,

This invention relates to the manufacture of electric-railway-railbonds, especially of that class wherein the terminals or rail-attachingstuds are fixed on the extremities of a flexihle'connector consisting ofa number of separate wiresor bars or a piece of ordinary wire cable,such terminals and connector being usually of copper.v As it isdesirable that there should be no appreciable resistance between theconnector and its terminals, various plans have been adopted to secure aclose contact. A'Ihe ends have .been placed in a mold and molten copperpoured in to fill around the connector and formthe stud, and while bothterminal and connector are at a high temperature a drop-hammer isapplied to consolidate the parts together.' plan is to form theterminals first, by casting or otherwise, then insert lthe cable orconnector, bring both up to a welding temperature,

and thenpress them into a substantiallywelded condition. In all methodsinvolving the application of heat the high temperature causes the rapidformation of oXid on the connector itself, thus appreciably reducingits.

conductivity, and it practically prohibits the use of insulation on theconnector.

In practicing my invention I do not raise the temperature of, the cableor connector, bnteiect the union of the parts cold, thus avoidingoxidation and obtaining a number of advantages.

To this and other ends my invention consists in the manufacture ofelectric connecting devices-such as railway-rail bonds,dynamo-terminals, &c.-by swagug the parts together by great pressureapplied cold, substantially as hereinafter fully described and claimed.

In the drawings which form part of this Another,

specification, Figure 1 is a sectional view civ Fig. v5 shows a plan andedge view of the' same with the cable inserted.V and `the two coldswagedtogether. Fig. 6 shows an edge and plan view of a bus-bar coupling orclamp and iiexible'connector cold-swaged together.

For making rail-bonds I use a shaping-die A, a confining-die B, and aplunger C. The precise shape of the working parts of thesev will dependupon the shape to be given the terminal. I show one end of a rail-bondcomposed of the rail-attaching stud d, its head e, and the flexiblecable f.

The confining-die B may have a cavity g cut in it, as shown, for formingpart of the head e, or the shoulder-cavity h may be recessed deeplyenough in the die Ato avoid making any cavity in the die B. The die Ahas a hole '1T bored through it, the lower 'por-A tion being tapered tofacilitate withdrawal of the pressed terminal. The plunger C is arrangedto enter the hole t' and, if desired, may be attached to the platen ofthe press.

I take a cast or drop-forged copper terminal approximating the desiredfinished form, as shown in Fig. l, having a holeV or socket formed in ittransversely to receive the end of the terminal f. This hole may beround; but I prefer a flattened or elliptical form, as shown.v 'I preferto clean the terminal with acid or otherwise and remove all oxid orscale and dirt from the surface, leaving the latter bright anduntarnished. The end of the cable f is then inserted in the hole, asshown in Fig. 1, and the dies are brought together,

after which great pressure is applied by meansl of the plunger C,actuated by a suitable press. This presses upon the end of the stud d.As the pressure increases the metal of the terminal is compelled to lowand fill all the cavities in the mold or die, consoli-4 dating the wholemass of the wires of cable f in IOO and with the head e and the stud d.By this method of swaging cold and under great pressure I produce aclose union of the wires of the cable with the terminal d e, an effectwhich I call cold Welding. Thel effect of the great pressure isillustrated in Fig. 3, Where it is seen that the metal of the terminalfills the external crevices of the cable, the

voids in the cable have been eliminated, and the originally-round Wiresare pressed into hexagonal shape, bringing all the surfaces into suchintimate and' cohesive contact as to constitute a weld for the purposesintended and without the possibility of oxidationvor burning byoverheating.

lVhile the invention is thus designed and shown as especially applicableto the manufacture of rail-bonds, various other electrical applicationscome within its scope. alnple, Figs. 4 and 5 illustrate it as applied todynamo-terminals. For large generators the connections between themovable brushholders ,andthe stationary counectiomboard of the machineare usually made of very flexible cable, and the cable is covered withinsulation. The terminals are usually attached by soldering, withresulting im perfect and uncertain conductivity and damage to theinsulation by heat. I make such a terminal T of soft copper, with thesocket s', into which the end of the cable f is inserted, and then byusing appropriate dies and great pressure I swage the whole mass intothe abovedescribed condition of a cold weld, as in Fig. 5, aord'i'ngperfect conductivity without injury to thelinsulation on the remainderof the cable.

In Fig. 6 I shoiv the same method applied to the socketm of a clamp nfor attaching a branch cable f"-to the bus-bar P of a switchboard. Inpractice I find that a pressure of about one hundred thousand pounds persquare inch is well adapted to effect the desired result.

As compared with the usual soldered connection my cold-Welded terminalshave the important advantage that under an overload of electric currentthere is no solder to melt and run out and make trouble.

Having described my invention, I claim as nev'v and desire to secu re byLetters Patentl. The method of uniting an electrical conductor toametallic terminal, which consists in inserting one into the otherandcold-welding them together by pressure.

2. The method of uniting an electrical conductor to a metallic terminal,consisting in inserting one into the other and cold-swagin g them intomutually-coherent homogeneous masses.

3. The method of uniting an electrical conductor to a metallic terminal,consisting in inserting the conductor into the terminal and swaging thetwo together under pressure sufficient to cold-weld the contactingsurfaces.

4. The method' of manufacturing railbonds, consisting in fitting theends of a flexible conductor into suitably-shaped terminals and swagingthe parts together under pressure sufficient to cold-Weld the contactingsurfaces.

5.v An electrical connection composed of asuitably-shaped terminal and aflexible conductor swaged and cold-welded together.

6. A rail-bond consisting of a flexible conductor and terminals havingshoulders and attaching-studs, said terminals and conductor being swagedand cold-welded together.

In testimonywhereof I aix my signature in presence of two witnesses.

' THOMAS J. MCTIGIIE.

Witnesses:

Trios. A. CoNNoLLY, Jos. B. CoNNoLLY.

